Adapter for photoflash lamps



-April 28, 1959A J. K.,|?o| Hl 5n/llusv "ADAPTER vFOR PH'oToFLAsH Lluviasl Filed Sept. 4. v1956 /N Al 'F IG. 4

INVENTOR .K. POLHEMUS y United States Patent O ADAPTER FOR PHOTOFLASH LAlVIPS John Kenneth Polhemus, Endwell, N.Y., assignor to General Aniline & Film Corporation, New York, N. a corporation of Delaware Application September 4, 1956, Serial No. 607,851 3 Claims. (Cl. 339-45) This invention relates to photographic flash guns and more particularly to an adapter for such guns for accommodating a particular type of ash lamp.

Flash guns for use with photographic cameras generally include an ejector mechanism for the quick removal of the used bulb and are designed to accommodate a certain type of bulb which will t the particular gripping device of the ejector mechanism. At the present time, the bayonet-type base is most commonly used for flash lamps, and the gripping mechanism of ash guns includes some instrumentality which engages the bayonet pins of the lamp base to hold it in the socket and releases it when the lamp is to be ejected.

Certain flash lamps of the miniature variety have a diierent base construction in that the base diameter is smaller than standard bayonet-type lamps and, instead of having pins extending from the base, have a circumferential groove. These ash lamps will not t any of the bayonet-type flash gun sockets and, for this reason, adapters are required which will retain the miniature lamp base by suitable engagement with the circumferential groove and also t the bayonet-type socket of the flash gun. Adapters of this type, however, while accommodating the miniature base lamps will not perform the function of ejecting the lamp after use by means of the ejector mechanism of the flash gun. In most cases, the adapter either ejects together with the lamp and must be reinserted every time or a separate release is provided in the adapter for removal or ejection of the miniature lamp.

The present invention has for its primary object the provision of an adapter which will accommodate miniature flash lamps having a circumferential groove for use with standard bayonet-type flash guns.

It is a particular feature of the invention that the adapter so constructed will also eject miniature lamps when the release mechanism of the flash gun is operated as it would standard bayonet-type base lamps.

Another feature of the invention is that the adapter, in accordance therewith, is simple in construction, has no separate release mechanism, and may be used in various types of flash guns.

Other objects, features and advantages will be apparent from the following description of the invention, pointed out in particularity in the appended .claims and taken in connection with the accompanying drawing, in which:

Fig. 1 is a perspective view of the adapter;

Fig. 2 is an exploded view thereof indicating the relative positioning of the parts and their assembly;

Fig. 3 is a sectional view of Fig. 1;

Fig. 4 is a sectional view of a bayonet-type flash gun having ejector mechanism in which the adapter can be used;

Fig. 5 is a similar view Ashowing the placement of the adapter, with the retention of a miniature ilash lamp; and

Fig. 6 is a view similar to Fig. 5 with the ejector mecha- ICC nism in operation and the ash lamp partially ejected from the adapter.

Referring in detail to Figs. 1, 2 and 3, the simple construction of the adapter will be apparent consisting of an insulating support 6 of cylindrical cross section which may preferably be of molded plastic material. At opposite sides, along the support 6 are channels 7, 7 which accommodate the gripping members 8, 8', respectively, consisting of particularly shaped llat springs. These are mounted on the inner face of the collar 10 of the support 6 by means of the rivets 11 and 12 which also serve to hold the ange 13 against the outer face of the collar 10.

The inner face of the gripping members 8, 8 is punched out to form a small lip 9, 9 which, when assembled in the support 6, extends inwardly for the purpose of engaging the groove of the miniature ash bulb. The ofrset portion of the members 8, 8 extends bilaterally from the support 6 and engages the ejector mechanism of the ash gun.

A central opening extends inwardly in the base 6 to accommodate ejector spring 15 which slips over the pin 16, the latter forming the electrical contact for the central contact of the ash lamp as will be seen later.

The sectional view of Fig. 3 shows the inner construction of the support 6, having a cylindrical cavity which is coaxially aligned with the opening in the ange 13 to permit insertion of the base of the miniature ash bulb. The side walls of the support 6, forming the cavity, have oppositely disposed cutouts 17 through which the inner face of the gripping members 8, 8 protrudes, particularly the lips 9, 9', respectively.

Referring to Fig. 4, the sectional view represents a certain type of flash gun socket which will operatively accommodate the adapter. Various other types of flash gun assemblies will also accommodate the adapter provided that these ash guns utilize a hook-like gripping member which engages the pin of the standard bayonettype ash lamp and these hooks are expandable to release the lamp.

The lamp socket comprises a casing 18 made of any suitable insulating material having an opening at the front surrounded by a collar 19 having oppositely disposed pins 20 for receiving a reflector 21. Positioned within the open end of the casing, and suitably anchored thereto, is a cylindrical metal socket sleeve 22 which is adapted to receive the conventional bayonet base flash bulb provided with radially extending locking pins.

The sleeve 22 has a pair of oppositely disposed grooves 23 to permit passage of the bayonet locking pins of the ash bulb. Coextensive with the grooves 23, cutout portions 24 are formed in the wall of the sleeve. At the inner end of the cutout portions there are provided surfaces 25.

The rear end of the casing 18 is recessed at 26 to receive a sliding button 29, the tip of which extends beyond the casing. A U-shaped spring 30 has its base anchored to the button 29 whereby movement of the button will cause movement of the spring 30. The legs of spring 30 normally extend into the cutout portions 24, and are provided with inwardly inclined hook portions 31 which snap over the locking bayonet pins of the conventional bulb.

The button 29 is bored to receive a plunger 32. The forward end of the plunger has a depression 33 to receive the base Contact of the bulb. A coil spring 34 is interposed between the socket portion 33 and a washer 35 positioned against the inner end of the button 29.

The electrical connections are obtained for the side contacts of the flash bulb through the engagement of the bayonet pins with the hook portions 31 of the spring 30.

The central electrical contact is by engagement with the plunger 32 and may be taken off from the washer by suitable connection.

Now, referring to Fig. 5, it is seen that the adapter in accordance with Vthis invention, when inserted into the socket of the flash gun, takes the place of the base of theconventional bayonet-type 'flash lamp. it is'held within the ash gun by the outer rim of the flange 13 being clamped against the collar 19 by the reector 21. Once so inserted, it remains permanently in the flash gun until the reflector is detached for removal of the adapter. The gripping members 8, are now compressed tightly against the support 6 by engagement with the legs of the U-shaped spring 30 so that the lips 9, 9 extend inwardly to engage the groove 35 of the base 39 of the miniature flash bulb 40. The spring 15 is also engaging the tip of the base 39 and the electrical contact is now completed through the pin 16 which nestles in the depression 33 of the plunger 32.

After the ash bulb has been used, depression of the button 29 causes the legs of the U-shaped spring 3G to expand by virtue of the fact that the hook portion 31 thereof must ride against the surface 25, which is inclined at such an angle to provide sufficient expansion of the spring 30. Due to the resiliency of the gripping members 3, these also expand, following the movement of the spring 3) and disengage the lips 9, 9' from the groove 38. The spring 15 having been depressed is now free to exert its force to expel the flash bulb l0 from the socket portion of the adapter. When the button 29 yis released, the parts again return to the position shown in Fig. ready for the insertion of lanother miniature ash lamp for the next exposure.

I claim:

1. An adapter for permitting photoash lamps of the miniature type having a circumferential groove around the base to be held in and ejected therefrom comprising a substantially cylindrical, recessed, insulating member provided with a collar at one end thereof, a ange attached to said collar, said one end of the member being open and adapted to receive the base of said lamp, two elongated at spring gripping elements, one positioned at each of two opposite sides and exteriorly of said member, one end of each of said elements being secured to said collar with said elements extending therefrom toward the other end of said member, the other ends of said elements being free to move toward and away from each other, said elements being provided with lateral projections extending into the recess of said member through openings in the wall of lsaid member located adjacent said collar, said projections being adapted to t into thegroove of the base o-f a lamp positioned in said recess to retain .said lamp in position, an ejection spring located within thel recess adjacent said other end of the member and adapted to c ontact the base of a lamp and be compressedxthereby, and a pin projecting through an opening insaid other end of the member and in contact with said spring.

2. An adapter for permitting photoash lamps of the miniature type having a circumferential groove around the base to be held in and ejected from the socket of a ash gun designed to retain an-d eject a lamp having a base provided with pins projecting therefrom and which socket has an open end provided with slots for said pins to permit insertion of the lamp, and which socket also has expansible retaining means for Ygripping said pins and ejection means for said lamp including means for expanding the retaining means to free said pins for ejection, said adapter `comprising a substantially cylindrical recessed insulating member having one end open to receive a miniature type lamp, a yflange attached to said open end for securing the member to the open end of the socket, elongated resilient expansible gripping means attached at one end tof-said member at the open end thereof, and extending exteriorly of the member toward the other end thereof, the other end of said gripping means being unattached to said member, said gripping means being provided with lateral projections extending into the recess through openings in the sides of the member to engage the groove in the miniature lamp to retain it in position, said gripping means vbeing shaped and positioned to tinto said slots and be retained in gripping position by said retaining means, a pin and ejector spring located centrally in said recess, said pin projecting from said other end of said member and said ejector springbeing adapted to engage the base of the miniature lamp, whereby upon actuation of the ejection means of the socket and expansion of the retaining means the gripping means are permitted to expand enabling the ejector spring to eject the miniature lamp from the adapter.

3. vThe combination of a socket adapted to retain and eject a lamp having pins extending from the base thereof with an adapter adapted to retain and eject a lamp having a base with -a groove therein, said combination comprising a socket comprising a substantially cylindrical casing having an open end and provided at said end with means forminggrooves to permit the entry of a base of a lamp having pins projecting therefrom, expansible retaining means in said casing for said lamp, said retaining means including hook portions adapted to grip said pins, ejecting means including means to expand said retaining means to` free said pins and a spring for ejecting'the lamp upon expansion of said retaining means, andan adapter positioned in said open end of the casing, said adapter comprising an insulating cylindrical, recessed member provided with a collar and a ilange at one end thereof removably securing the member to the casing, said end being open and adapted to receive the base of a lamp having a groove therein, resilient expansible gripping members extending along the exterior of said insulating member -and secured at one of their ends to said collar, the other ends of said gripping members being free, said gripping vmembers being positioned insaid grooves and retained in gripping position by the engagement of the hook portions of said retaining means with the free ends of the gripping members, said gripping members having portions extending into the recess of said insulating member for rengaging the groove in the Vbase of the lamp, andan electrically conductive pin f and an ejector spring located centrally in the recess, said References Cited in the le of this patent UNITED STATES PATENTS Brundage May `13, 1952 Lawson Oct. 5, 1954 

